From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id C1D21D116EA for ; Sat, 29 Nov 2025 03:55:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=1dCa0Yi2abB18gZnNstjxBDy+4BryzpI37joEvmB9nM=; b=1HiKY914pV2fpX9MfI7tPYwTeO dk3yogDW/XWYj3jjc4vra20k5z6Lg/bgNnq31tksLahwVG02unO6IWfPFTKpwmw8foyEEkVjHspkd 2BL/MgGE9cMuct+iE0D1caUqDrrlYWgx1Lq1tkqViZFRnhulGOYItA8o07S/lNui0xHI1w+Mds7gO lKS5b4j6jwfqLoMTclZYhIwtMHrxr0iqYkFth4VT+Pb8oID3VO14aofnHyVIUszVYaawhBFN946oI hIPklSMj7xbNlUqVkCkvHGbU1qZox8frklkRvbqEDcyZDuTE1jlZJjVCeWrt2/BslZnAhYaf1ZGrK cDZwDmzg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1vPC3D-00000001FOQ-3C9v; Sat, 29 Nov 2025 03:55:11 +0000 Received: from zeniv.linux.org.uk ([2a03:a000:7:0:5054:ff:fe1c:15ff]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1vPC3B-00000001FNJ-1xpm for linux-arm-kernel@lists.infradead.org; Sat, 29 Nov 2025 03:55:10 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=linux.org.uk; s=zeniv-20220401; h=Sender:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=1dCa0Yi2abB18gZnNstjxBDy+4BryzpI37joEvmB9nM=; b=gif53AQXc1RzHnygPbDtIU0X9L pXTFfokzhGNWnuy66xDaEH/e5OK0oyUdCm4pbTUKtbbksPMcXlqSNS0VCZDb2SJIB9J/PGAbtpqbG CO8OW3uSLvzVc3N7Das2tMfFe7RiY/yna+fzkylq+2CW5cGxecl6dTfKxhJgvWdBBeoPwcIyDFC2s 8sQLhqsD1hjniYUK2XVRqXshs+TJ0gYBdaxjzN6imMaYMF+GPISY28ftXIfPzc78DeU0qhSE93uU7 +1dLgV4XxZb7onQ+ybhE2DK6uXuf5i3CZdI074nrQAY1XXegzlcxto0oJi2wynNGH9zvSxytr5yAR kywVSLoA==; Received: from viro by zeniv.linux.org.uk with local (Exim 4.99 #2 (Red Hat Linux)) id 1vPC3C-00000000XUf-1HpY; Sat, 29 Nov 2025 03:55:10 +0000 Date: Sat, 29 Nov 2025 03:55:10 +0000 From: Al Viro To: Zizhi Wo Cc: Will Deacon , Linus Torvalds , jack@suse.com, brauner@kernel.org, hch@lst.de, akpm@linux-foundation.org, linux@armlinux.org.uk, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-arm-kernel@lists.infradead.org, yangerkun@huawei.com, wangkefeng.wang@huawei.com, pangliyuan1@huawei.com, xieyuanbin1@huawei.com Subject: Re: [Bug report] hash_name() may cross page boundary and trigger sleep in RCU context Message-ID: <20251129035510.GI3538@ZenIV> References: <20251126090505.3057219-1-wozizhi@huaweicloud.com> <9ff0d134-2c64-4204-bbac-9fdf0867ac46@huaweicloud.com> <39d99c56-3c2f-46bd-933f-2aef69d169f3@huaweicloud.com> <61757d05-ffce-476d-9b07-88332e5db1b9@huaweicloud.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20251128_195509_535134_E767717F X-CRM114-Status: GOOD ( 10.62 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Sat, Nov 29, 2025 at 09:02:27AM +0800, Zizhi Wo wrote: > Thank you very much for the answer. For the vmalloc area, I checked the > call points on the vfs side, such as dentry_string_cmp() or hash_name(). > Their "names addr" are all assigned by kmalloc(), so there should be no > corresponding issues. But I'm not familiar with the other calling > points... Pathname might be a symlink body, sitting in page cache or whatever ->get_link() has returned...